The pitfalls and problems which trips you up managing Gastric NET's

​Professor Mark Pritchard, has a simple plea; when you are dealing with gastric NET's, make sure that you know what you are doing!  In this Podcast he highlights the pitfalls and provides us with Endoscopy Gold !!! 
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Below is a reminder of the main points discussed in the Podcast with key references 

AT ENDOSCOPY:
• Look for atrophic gastritis 
• Consider using some pH indicator strips to measure the gastric pH (unless pt is taking PPI)
• Identify all the NETs, record their size and number and sample them for histology and grading
• Take antral and corpus biopsies and ask pathologist to do report on the presence/absence of gastric atrophy and intestinal metaplasia and also ask them to carry out immunohistochemistry stains for ‘gastrin’ in the antral biopsies and ‘chromogranin’ and ‘synaptophysin’ in the gastric body samples.
• Look into the second part of the duodenum for the small submucosal gastrinomas which occasionally are seen in MEN-I
• Consider samples for Coeliac disease if the patient has IDA

CONSIDER OFFERING ENDOSCOPIC RESECTION FOR:
• type I gastric NETs   if >10-15mm
• type II gastric NET   if they’re causing problems (eg bleeding) and/or gastrinoma can’t be resected
• type III gastric NET <1cm (provided that it's no worse grade 1/low grade 2 !)

HISTOLOGY:
If that proliferative index comes back surprisingly high (>10%), make sure that the pathologist hasn't inadvertently counted Ki67 positive cells in the nearby gastric mucosa. Atrophic gastric mucosa is usually more proliferative than the NETs! 

BLOOD TESTS:
• FBC
• Full haematinic screen including B12 and Ferritin of course
• TFTs
• Anti-parietal cell AB & Intrinsic factor AB titres
• Serum gastrin level
• Chromogranin level
• Calcium and PTH level (particularly if MEN1 is suspected)

REQUEST THE FOLLOWING SCANS FOR EVERYONE WITH LIKELY TYPE II AND III DISEASE:
• CT
• 68Gallium DOTA-peptide PET/CT scan
• EUS to search for duodenal wall gastrinomas and small gastrinomas within the pancreas which CT can't see and to search for lymphadenopathy close to the NET


REFERENCES
Exarchou, K. et.al. Systematic review: management of localised low-grade upper gastrointestinal neuroendocrine tumours. APT 2020;51(12): 1247-67  

Exarchou, K. et.al. Type III Gastric Neuroendocrine Neoplasms: Is Local Excision Sufficient in Selected Cases? NEUROENDOCRINOLOGY March 2020 Meeting Abstract: L03  Volume: 110  Pages: 283-283  Supplement: 1

Exarchou, K. et.al. Periodic endoscopic surveillance in patients with low risk Type 1 gastric neuroendocrine tumours (gNETs) also detects associated gastric adenocarcinoma in a subset of patients. Br J Surg 2019;106( Special Issue: SI):85-85  Supplement: 7

Boyce, M et.al. Netazepide, a gastrin/cholecystokinin-2 receptor antagonist, can eradicate gastric neuroendocrine tumours in patients with autoimmune chronic atrophic gastritis. Br J Clin Pharm 2017;83(3):466-75  

Murugesan SV et.al. Correlation between a short-term intravenous octreotide suppression test and response to antrectomy in patients with type-1 gastric neuroendocrine tumours. Eur J Gastro Hep 2013;25(4):474-81